111 Classification of the Soils – Castlecrest Series

Classification of the Soils

Castlecrest Series

Depth class: Very deep

Drainage class: Somewhat excessively drained

Permeability: Rapid

Position on landscape: Mountain flanks and mountainsides

Parent material: Pumice and ash

Slope range: 0 to 80 percent

Elevation: 5,000 to 8,000 feet

Average annual precipitation: 40 to 70 inches

Average annual air temperature: 38 to 42 degrees F

Frost-free period: 0 to 50 days

 Taxonomic class: Ashy, amorphic Typic Vitricryands

 Typical Pedon

 Oi—0 to 1 inch; slightly decomposed needle litter; abrupt wavy boundary.

A—1 inch to 3 inches; very dark grayish brown (10YR 3/2) paragravelly ashy loamy sand, dark grayish brown (10YR 4/2) dry; single grain; loose, nonsticky and nonplastic; common fine and medium roots; many fine interstitial pores; 15 percent pumice paragravel; slightly acid (pH 6.2); clear smooth boundary.

Bw—3 to 19 inches; brown (10YR 4/3) paragravelly ashy loamy sand, brown (10YR 5/3) dry; single grain; loose, nonsticky and nonplastic; common fine and medium roots; many fine interstitial pores; 15 percent pumice paragravel; slightly acid (pH 6.2); clear smooth boundary.

C1—19 to 26 inches; very dark grayish brown and dark grayish brown (10YR 3/2 and 10YR 4/2) ashy sand, brown (10YR 4/3 and 10YR 5/3) dry; single grain; loose, nonsticky and nonplastic; many fine interstitial pores; 7 percent pumice paragravel; slightly acid (pH 6.4); clear wavy boundary.

C2—26 to 38 inches; gray and very dark gray (10YR 6/1 and 10YR 3/1) ashy coarse sand, light gray and dark grayish brown (10YR 7/2 and 10YR 4/2) dry; single grain; loose, nonsticky and nonplastic; many fine interstitial pores; 5 percent pumice paragravel; slightly acid (pH 6.4); gradual wavy boundary.

C3—38 to 64 inches; light yellowish brown and very dark gray (10YR 6/4 and 10YR 3/1) ashy coarse sand, very pale brown and dark grayish brown (10YR 7/4 and 10YR 4/2) dry; single grain; loose, nonsticky and nonplastic; many fine interstitial pores; 5 percent pumice paragravel; slightly acid (pH 6.4).

Typical Pedon Location

 Map unit in which located: Unionpeak-Castlecrest-Sunnotch complex, 0 to 15 percent slopes

Location in park: About 2.3 miles east-northeast of the Pumice Desert viewpoint; 568327 meters easting and 4765143 meters northing,

UTM Zone 10T, NAD 27; lat. 43o2’15.65″ N., long. 122o9’44.53″ W.

 Range in Characteristics

 Profile:

Depth to bedrock—more than 60 inches

Thickness of solum—14 to 30 inches

Average content of rock fragments and pararock fragments—less than 35 percent

Hue—7.5YR or 10YR

An albic (E) horizon as much as 3 inches thick is in some pedons (fig. 8).

A horizon:

Value—2 to 5 moist, 3 to 6 dry

Chroma—2 to 4 moist or dry

Texture—ashy sandy loam, ashy loamy sand, gravelly ashy sandy loam, gravelly ashy loamy sand, and paragravelly ashy loamy sand

index.8

Figure 8.—Typical profile of a Castlecrest soil. Note the white, discontinuous E horizon at a depth of about 4 inches. Measurements on tape are in feet.

Content of pumice paragravel—0 to 15 percent

Content of cinder gravel—0 to 8 percent

Content of andesite gravel—0 to 15 percent

Content of andesite cobbles—0 to 3 percent

Bw horizon:

Value—3 or 4 moist, 4 to 6 dry

Chroma—2 to 4 moist or dry

Texture—ashy loamy sand, ashy sandy loam, or ashy sand

Content of pumice paragravel—0 to 15 percent

Content of cinder gravel—0 to 5 percent

Content of andesite gravel—0 to 20 percent

Content of andesite cobbles—0 to 3 percent

C horizon:

Value—3 to 6 moist, 4 to 7 dry

Chroma—1 to 6 moist, 2 to 6 dry

Texture—ashy sand, ashy coarse sand, or ashy loamy sand

Content of pumice paragravel (upper part)—0 to 15 percent

Content of pumice paragravel (lower part)—0 to 60 percent

Content of cinder gravel—0 to 20 percent

Content of andesite gravel—0 to 15 percent

Content of andesite or cinder cobbles—0 to 2 percent

 

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